NumberResearch Membership · Data 09/20/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/20/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, all time — NPA 310
U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 24
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
— 310-321 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J EL SEGUNDO CA
— 310-432 3XXX which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J BEVERLYHLS CA
— 310-436 4XXX5XXX · 2 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J CMTN GRDN CA
— 310-461 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J BEVERLYHLS CA
— 310-484 3XXX4XXX5XXX6XXX8XXX9XXX · 2 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J INGLEWOOD CA
— 310-506 0XXX9XXX which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J MALIBU CA
— 310-566 not yet reported which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J SNMN SNMN CA
— 310-623 0XXX2XXX7XXX9XXX · 2 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J BEVERLYHLS CA
— 310-696 0XXX1XXX2XXX3XXX4XXX6XXX8XXX9XXX · 3 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J W ANGELES CA
— 310-698 1XXX2XXX3XXX6XXX9XXX · 4 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J REDONDO CA
— 310-706 1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J HAWTHORNE CA
— 310-707 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J SAN PEDRO CA
— 310-746 3XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J BEVERLYHLS CA
— 310-747 2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 7 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J CMTN CMTN CA
— 310-755 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J TORRANCE CA
— 310-806 0XXX1XXX2XXX3XXX5XXX7XXX8XXX which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J W ANGELES CA
— 310-818 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 8 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J CMTN GRDN CA
— 310-856 1XXX5XXX9XXX · 2 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J CMTN GRDN CA
— 310-857 0XXX2XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J SNMN SNMN CA
— 310-873 3XXX6XXX7XXX8XXX · 2 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J W ANGELES CA
— 310-881 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J SNMN MRVS CA
— 310-883 0XXX3XXX4XXX5XXX7XXX8XXX · 5 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J SNMN SNMN CA
— 310-896 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX · 6 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J REDONDO CA
— 310-904 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → U.S. TELEPACIFIC CORP. DBA TPX COMMUNICATIONS 671J CULVERCITY CA

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/20/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.